procedure MPROVE(A,ALUD:matrx2; N:integer;
            INDX:array of real; B:array of real;var X:array of real);
var
    R:array [0..100] of real;
    I,J:integer;
    SDP:real;
begin
    For I:=1 To N do
    begin
        SDP:=-B[I];
        For J:=1 To N do
            SDP:=SDP + A[I, J] * X[J];
        R[I]:=SDP;
    end;
    LUBKSB(ALUD, N, INDX, R);
    For I:=1 To N do
        X[I]:=X[I] - R[I];
end;